Arjun Vishaad Yog-Bhagavad Gita Chapter 1 [Observing the Armies on the Battlefield of Kurukshetra]
Sanjaya Said > Shaloka: 3
O my teacher, behold the great army of the sons of Pandu, so expertly arranged by your intelligent disciple, the son of Drupada.
Duryodhana, a great diplomat, wanted to point out the defects of Dronacarya, the great brahmana commander-in-chief. Dronacarya had some political quarrel with King Drupada, the father of Draupadi, who was Arjuna’s wife. As a result of this quarrel, Drupada performed a great sacrifice, by which he received the benediction of having a son who would be able to kill Dronacarya. Dronacarya knew this perfectly well, and yet, as a liberal brahmana, he did not hesitate to impart all his military secrets when the son of Drupada, Dhrstadyumna, was entrusted to him for military education. Now, on the Battlefield of Kuruksetra, Dhrstadyumna took the side of the Pandavas, and it was he who arranged for their military phalanx, after having learned the art from Dronacarya. Duryodhana pointed out this mistake of Dronacarya’s so that he might be alert and uncompromising in the fighting. By this he wanted to point out also that he should not be similarly lenient in battle against the Pandavas, who were also Dronacarya’s affectionate students. Arjuna, especially, was his most affectionate and brilliant student. Duryodhana also warned that such leniency in the fight would lead to defeat.